Apparatus for generating directed high frequency sound waves



March 5, 1957 I. CHERTOFF APPARATUS FOR GENERATING DIRECTED HIGHFREQUENCY SOUND WAVES Filed July 22, 1953 mum/Ton. f5 erfof/ UnitedStates Patent cc APPARATUS FOR GENERATING DIRECTED HIGH FREQUENCY SOUNDWAVES The present invention relates to an apparatus for generating highfrequency sound waves.

In U. S. patent application Serial No. 284,091 of April 24, 1952, ofwhich this application is a continuation-inpart, an apparatus forgenerating directed high frequency sound waves is disclosed, the saidapparatus comprising mounted fixedly within the throat of a Venturi tubea hollow cone having a. series of openings and a hollow rotary conenesting with the said fixed cone and having a series of Venturi openingsin register with the openings of the fixed cone. When air or anothergaseous medium is blown through the Venturi tube and the rotary cone isturned at high speed, sound waves are created at frequencies above theaudible range. The device is very effective in disintegrating anddispersing liquid dropletsinjected into the gaseous stream.

The advantage of the afore-mentioned cone-shaped mechanism for producinghigh frequency sound waves lies inthe fact that the sound waves aredirected toward a focal point. As a result, atomization of liquiddroplets dispersed at or near the focal point takes place at far greaterefliciency than by means of prior devices producing audio waves atrandom distribution.

The present disclosure relates to improvements in the afore-describeddevice. One improvement is a substantial increase in the relative speedat which the sets of openings in one cone rotate past the sets ofopenings in the other cone, resulting in much higher frequencies. Theother improvement relates to a further concentration of waves and to theproduction of a cumulative ultrasonic effect within the desired regionof the Venturi tube by means of a reflector especially designed topermit substantially unimpeded flow of the gaseous medium.

It is, therefore, one object of the present invention to provideimproved means for generating directed high frequency sound waves and toprovide means for reflecting such sound waves to a focal point within aVenturi tube adapted for high speed passage of a gaseous medium.

It is another object of the invention to use the focalizing effect ofthe device upon high frequency sound waves produced therewith to atomizedroplets of liquid injected into a gaseous stream, such as droplets offuel or fuel and water for the operation of an internal combustionengine.

Other objects of the invention will in part be obvious and in parthereinafter be pointed out.

In the accompanying drawings, showing an illustrative embodiment of theinvention:

Fig. 1 is a sectional view along the axis of the device,

Fig. 2 is an enlarged view of one of the relief valves,

Fig. 3 is a cross-sectional view taken on the line 3-3 in Fig. 1, and

Fig. 4 is a cross-sectional view taken on the line 4-4 in Fig. 3.

Referring in more detail to the drawings, the numeral designates a tubehaving a Venturi-shaped constriction 11. Arranged within the tube asshown are the three spiders 12, and 18 which are formed with centralhubs 13, 16 and 19, respectively. Mounted within these hubs are ballbearings, such as the ball bearings 14 and 20.

Extending from the hub 13 and journalled to be retained in position bythe said hub is the shaft 23 which has a hollow cone 24 attached to thefree end thereof. This cone is provided with a plurality of circularlyar ranged openings such as the opening indicated at 25. The shaft 23 andthe cone 24 are held in an accurate, spaced co-axial position withrespect to a hollow shaft 26 by means of the ball bearing 21 arrangedshortly below the cone and by means of a similar ball bearing arrangedwithin the hub 16. The hollow shaft 26 expands at its upper end into ahollow cone 27 nesting with the aforedescribed cone 24. Being ofsubstantial wall-thickness, the hollow cone 27 is provided with aplurality of circularly arranged, Venturi-shaped openings, such as theopening 28, which are in linear register with the openings cut into thecone 24.

Arranged flush with the hollow cone 24 is a collar 30 provided with anumber of valves such as the valve 31. The lids 32 of these valves arefastened to the collar by means of the hinges 33 and, in the absence ofexcessive gaseous pressure, are held in a closing position by thetorsion springs 34.

The free end of the hollow shaft 26 is fixedly attached .to the hub 36of a gear wheel 37, forming part of a right angle bevel gear systemcomprising the said gear wheel,

a driven gear wheel 38 having a drive shaft 39 adapted to be coupled toa rotatory power source such as an electric motor, and the gear wheel 40supplying rotary motion to the shaft 23. As indicated in Fig. 3 at 41,the

cylindrical shape of the tube 10 is box-like enlarged in part toaccommodate the gear wheel 38 and the bearing 42 fitted through the wallof the tube.

The gear wheel 37 and the gear wheel 40 are provided with four spokeseach. These spokes, such as the spoke 45, are made relatively flat and,as shown in Fig. 4, are set at an angle so that, upon rotatiton of thegear wheels, the spokes will assume the function of blades of a fan orpropeller and cause a rapid motion of gaseous medium toward the Venturisection 11 as indicated by the arrows in Fig. 1.

Mounted fixedly inside the Venturi tube 11, preferably within the spacebetween the spiders 15 and 18, is a reflector to cast back propagatedultrasonic waves. Ordi narily, any suitable reflector of conical orparabolic shape would be suitable. However, due to the necessity ofmoving a gaseous stream toward the high frequency sound producingdevice, in order to retain the inherent simplicity of design, I have cutthe wall of the reflector into a spiral band 50 and have separated theindividual loops practically free passage of a gaseous mediumtherethrough. In the drawing, a reflector of conical shape is shown.Obviously, a parabolic reflector spirally opened in the same manner canbe used in place thereof. Moreover, by eliminating the spider 18 or bymoving the said spider further down if desired, the reflector can belocated closer to the cone 27.

As an illustration of the use of the device, the inlet pipes 51 and 52enter into the Venturi tube 11 arranged in such a manner that theirnozzles 53 and 54 are located next to each other within the focal regionofthe high frequency sound. Liquid droplets ejected from the nozzlesundergo an instantaneous and efiicient atomization.

It will be understood that, as the shaft 39 is rotated at high speed,the gear wheel 38 turns the gear wheel 37, the shaft 26 and the hollowcone 27 in one direction, while the gear wheel 40, the shaft 23 and thehollow cone 24 is turned in the opposite direction. The said geararrangement can be set up with toothed wheels or with Patented- Mar. 5,1957 whcelsmakingfrictional contact with each other. Due to thepropelling efiect of the blades 45, a gaseous stream moves at greatvelocity toward the cones and, in passing through the openings in therotating cones, produces high frequency sound waves converging at afocalpoint in front of their piaee of origin. Insofar as these sound wavesare capable of travelling backward, par-ticat'larly if the lids 32 areraised, they are again reflected forward by the spiral band 50.

The valves 31 are adapted to open it the back pressure created by thecones restricting the gaseous flow exceeds a predetermined point. Theholes cut into the cone 24 and the Venturi openings provided at the cone27 are preferably" arranged in registering circles, although there doesnot need to be the same number of openings in the respective circles,

Since it is possible-to reduce the invention to practice by means ofembodiments other than the embodiment disclosed without'departing fromthe spirit of the invention, it-

to be understood that all matter herein set forth is to beinterpreted asillustrative and not in a limiting sense.

I claim:

I. In an apparatus for generating directed high frequency sound waves,the said apparatus comprising a Venturi tube,- means for passing agaseous stream through the said Venturitube, mounted at the throat ofthe said Venturi tube aninternal flange carrying a plurality of springoperated valves adjusted to open upon a given pressure increment, fixedtransversely within the annular opening of. the said flange a firsthollow cone having series of openings and nesting with the said fixedcone a second hollow rotary cone which is thick-walled and has series ofVenturi-shaped openings in linear register with the series of openingsin the said fixed cone, the improve ment of mounting both of the conesrotatably, providing means for rotating the said cones in oppositedirections said second cone is mounted at one end of a hollow shaft andthe said first cone is mounted at one end of a solid shaft of lesserdiameter in order to pass through the said hollow shaft, right anglebevel gear wheels are attached to the other ends of the said shafts anda third right angle bevel gear wheel adapted to be turned by anappropriate power source is mounted to rotate the said shafts and thesaid first two gear wheels in opposite directions.

3. The improvement according to claim 2, in which the spokes ofthe gearwheels attached to the said shafts are given the shape and pitch ofpropeller blades to produce, upon rotation of the said gear wheels, arapid motion of gaseous medium toward the said cones.

4. The improvement according to claim 2, in which the said Venturi tubeis provided with a box-like enlargement at one side to accommodate thesaid third bevel gear wheel within the said tube.

5. The improvement according to claim 2, in. which the said bevel gearwheels are toothed wheels.

6. The improvement according to claim 1, in which the said spiralreflector is cut from a cone.

References Cited in the file of this patent UNITED STATES PATENTS1,939,302 Heaney Dec. 12, 1933 2,153,500 Eaves Apr. 4, 1939 2,364,987Lee Dec. 12, 1944 2,414,494 Vang Ian. 21, 1947 2,436,570 Hancock Feb.24, 1948 2,454,900 Vang Nov. 30, 1948 2,532,554 Joeck Dec. 5, 19502,535,680 Horsley et a1 Dec. 26, 1950

